Tape Cassette Having Internal Drive With Speed Adjustment

The present invention relates to tape cassettes.

Tape cassette players are designed primarily for driving tapes on which music is recorded and therefore in order to obtain reasonable quality reproduction from such cassette the tape must be recorded and played at a reasonably fast speed. Such quality reproduction, however, is not required where the material recorded does not have a musical content, for example, recordings of stories. Running the tape cassettes at the higher speeds required for musical reproduction is therefore very wasteful of tape.

Accordingly the present invention provides a tape cassette having an internal drive system for adjusting the tape transport speed to a value higher or lower than that provided by the drive system of a tape cassette machine.

The present invention is further described hereinafter, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 is a schematic plan view of a conventional tape cassette with the top removed;

FIGS. 2 to 5 are schematic plan views of four embodiments of a tape cassette according to the present invention in which the tape transport speed is less than that in a conventional tape cassette;

FIGS. 6 to 8 are schematic plan views of three embodiments of a tape cassette according to the present invention in which the tape transport speed is greater than that in a conventional tape cassette;

FIG. 9 is a sectional side view of a tape spool which can be used in any one of the cassettes shown in FIGS. 2 to 8;

FIGS. 10 to 12 are sectional views of three different forms of slipping clutch which can be used in any one of the cassettes shown in FIGS. 2 to 8, FIGS. 10 and 11 being sectional views and FIG. 12 being a sectional plan view;

FIG. 13 is a sectional side view of an alternative form of tape spool which can be used in any one of the cassettes shown in FIGS. 2 to 8;

FIGS. 14 to 18 are schematic plan views of five further embodiments of a tape cassette according to the present invention in which the tape transport speed is less than that in a conventional cassette;

FIG. 19 is a perspective view of a spring and a sleeve which form part of the cassette shown in FIG. 18;

FIG. 20 is a side view of the above-mentioned sleeve; and

FIG. 21 is a schematic plan view of a drive slip arrangement for a tape spool which can be used in any one of the cassettes shown in FIGS. 2 to 8 and FIGS. 14 to 18.

The conventional tape cassette 10 illustrated in FIG. 1 comprises two tape spools 12 and 14 over which a recording tape 16 is wound, the tape running from one spool 12 over an idler roller 18' past an erase head 26 of a cassette player, over a pressure pad 24 which serves to hold the tape against a record/play-back head (not shown) of the player, past a capstan 20 and a pressure roller 22 of the cassette player between which the tape is pinched, and around a further idler roller 18 to the other tape spool 14. In the drawings, the tape is normally driven in the direction of the arrow A, drive being applied to the tape via the capstan 20 of the cassette player.

FIG. 2 shows a first embodiment of a tape cassette according to the present invention in which a drive system 30 transports the tape at a slower speed than in a conventional cassette when the cassette is used in a conventional cassette recorder/player. Although the drive system is illustrated on the right-hand side of the cassette, it is to be understood that in this embodiment (and indeed in all of the embodiments described below) an identical drive system is also provided on the left-hand side of the cassette for use when the cassette is inverted. The drive system 30 comprises two idler rollers 32 and 32' of unequal diameter about which a drive band 34 is wound. The drive band is located such that when the cassette is inserted in the cassette player the drive band 34 is gripped between the capstan 20 and pressure roller 22 of the cassette player and is driven directly thereby. The larger of the two idler rollers 32' drives a further roller 36, of similar diameter which in turn drives a roller 38 of smaller diameter, the tape passing between these last two rollers. Drive is transmitted from the roller 38 to the spool 14 rim via a slipping clutch 40 which is maintained in engagement with the spool and the roller 38 by a spring 42, the normal hub drive of the spool from the cassette player being disconnected, as will be described in detail later. As illustrated, the idler roller 32 has an annular peripheral groove in which the drive band 34 is received, and the depth of this groove determines the transport speed of the tape, which is typically approximately one quarter of the standard speed. Illustrated at 44 are idler rollers and jockey pulleys which guide and lightly tension the tape.

FIG. 3 shows a second embodiment of a tape cassette according to the present invention which is generally similar to the arrangement shown in FIG. 2, similar parts being denoted by the same reference numerals but with 100 added. In the embodiment of FIG. 3, however, the drive band 134 passes behind the capstan 130 and is, therefore, moved in the opposite direction to FIG. 2. To allow for this, the tape 116 passes around the outside of the roller 136, around a further idler roller 146, and around the idler roller 132. The pressure roller 122 of the cassette player is prevented from contacting the tape by a plate 148 which is suitably pivoted about an axis 150 to allow the erase head to come into contact with the tape when required.

FIG. 4 shows a third embodiment of a tape cassette according to the present invention, in which the tape drive system again comprises a pair of idler rollers 160 and 162 around which a drive band 164 passes, the drive band being received in use between the capstan (referenced 166) and the pressure roller (referenced 168) of a cassette player. The recording tape (shown in broken line at 170) also passes between the capstan 166 and the pressure roller 168, but the drive band 164 being of greater thickness than the recording tape, provides sufficient clearance for the recording tape not to be contacted by the capstan or the pressure roller. In addition, the recording tape 170 passes around a reduced diameter portion of the idler roller 162 and is pressed between this portion and a pinch wheel 172.

FIG. 5 shows a fourth embodiment of a tape cassette according to the present invention in which a drive capstan 180 of a cassette player in use contacts an idler wheel 182 mounted on an arm 184, the latter providing a lift-off mechanism to clear the erase head of the cassette player. The idler wheel 182 is also engaged by a pressure roller 186 of the cassette player, the recording tape (referenced 188) being pinched between the idler wheel 182 and a pinch wheel 190. The pinch wheel 190 in turn engages a slipping clutch 192 which contacts a rim of the tape spool 193 to drive the latter, the slipping clutch 192 being mounted on a pivotal lever 194 with a guide wheel 196 around which the tape 188 passes. Using this arrangement, the tape transport speed can be reduced to about one quarter of that of a standard cassette. A further reduction in speed can be achieved by providing the idler wheel 182 with a reduced diameter portion and the pinch wheel 190 with an enlarged diameter portion, and by pinching the tape between these portions.

A fifth embodiment of a tape cassette according to the present invention is shown in FIG. 5 and is generally similar to that described above with reference to FIG. 2, similar parts being accorded the same reference numerals but with 200 added. However, the idler roller 232' now engages a reduced diameter portion of the further roller 236 so that the recording tape 216 (which is pinched between the roller 236 and the roller 238) is transported at a greater speed than in a standard cassette, rather than at a lower speed as in the case of the arrangement shown in FIG. 2.

FIG. 7 illustrates a sixth embodiment of a tape cassette according to the present invention in which the tape is again transported at a greater speed than in a standard cassette. The capstan (referenced 250) of a cassette player drives an idler wheel 252 which is also engaged with the pressure roller (referenced 254) of the cassette player. The idler wheel 252 in turn drives an idler wheel 256 via a further idler wheel 258, the latter engaging a reduced diameter portion of the idler wheel 256. The recording tape (referenced 260) is pinched between the idler wheel 256 and a wheel 262, the latter also engaging a slipping clutch 264 which provides a rim drive for the tape spool (referenced 266). A spring 268 biases the clutch 264 into engagement with the tape spool rim, and also urges the wheels into engagement.

FIG. 8 depicts a seventh embodiment of a tape cassette according to the present invention, in which the recording tape (referenced 270) is driven by the capstan (referenced 272) of a cassette player via a floating sleeve 274 which is guided and retained in a locating recess 276. The tape is pinched between the floating sleeve 274 and the pressure roller (referenced 278) of the cassette player, drive also being transmitted from the floating sleeve 274 to the rim of the tape spool (referenced 280) by means of a slipping clutch 282, which is maintained in engagement with the spool rim by a tension spring 284. By means of this arrangement, the tape transport speed can be increased to about double that for a standard cassette.

In a modification (not shown) of the last-mentioned embodiment, drive is transmitted from the floating sleeve 274 to the slipping clutch 282 not by direct engagement of these parts but instead by a drive band which passes around the floating sleeve and an idler roller engaged with the slipping clutch. In addition, a retaining idler (shown in broken line at 286 in FIG. 8) can be provided for retaining the floating sleeve 274 in the desired position.

In the above-described embodiments, it is assumed that the speed at which the tape spool is driven must be changed from the standard speed when the tape transport speed is increased or decreased from normal, and to this end the usual hub drive for the tape spool is replaced by a rim drive provided by a slipping clutch. The hub drive should, however, be retained when the cassette is inverted for tape to be wound onto the spool in the forward direction. FIG. 9 shows one form of tape spool 300 for use in a cassette according to the invention which allows this to happen. As in a conventional tape spool, the spool 300 has lugs 302 thereon which are engageable by axial splines 304 on a drive spindle 306 of a cassette player. However, the lugs 302 are disposed at one axial end of the spool, rather than centrally thereof as in a conventional cassette, so that they clear the ends of the splines 304 in one position of the cassette (as illustrated) and engage the splines when the cassette is inverted.

FIGS. 10, 11 and 12 illustrate three different forms of slipping clutch for use in the above-described embodiments. Each of the slipping clutches shown in FIGS. 10 and 11 has a driven wheel 310 which is bonded to a freely rotating spindle 312. A drive wheel 314 which is freely rotatable on the spindle 312 is biased by a spring 316 into frictional engagement with a flange 318 on the spindle 312. Drive is transmitted by this frictional engagement from the drive wheel 314 to the driven wheel 310 and thus to the tape spool rim. In FIG. 12, the slipping clutch comprises a drive wheel 320 having a plurality of flexible vanes 322 running axially thereof. Outer ends of these vanes contact an inner surface of an annular driven wheel 324 which is ffreely rotatable and engaged with the tape spool rim. By virtue of the frictional engagement of the vanes 322 with the driven wheel 324, the driven wheel rotates with the drive wheel 320 and thus transmits drive from the drive wheel to the tape spool rim.

FIG. 13 illustrates an alternative arrangement for modifying the speed of the tape spool which does not require the use of a slipping clutch rim drive. In this arrangement, the tape spool is split into two axially spaced portions 330 and 332, the tape being wound around an upstanding annular flange 334 of the portion 330 whereas the portion 332 is drivingly engaged with a drive spindle 336 of a cassette player. Radially outer edges of the portions 330 and 332 have teeth which mesh with respective differing portions of a gear wheel 338. As shown, the portion 332 of the tape spool engages a smaller diameter portion of the gear wheel 338 so that the tape is unwound from the portion 330 at a higher rotational speed than the drive spindle 336. The arrangement can, however, be modified so that the portion 330 rotates at a lower speed than the drive spindle 336 by engaging the portion 332 with a larger diameter portion of the gear wheel 338.

An eighth embodiment of a tape cassette according to the present invention is shown in FIG. 14, and has a tape drive system 400 which comprises two idler rollers 402 and 404 mounted in sliding tracks so that they can move in mutually perpendicular directions. As in conventional cassettes a hole 406 is provided in the cassette to allow entry of the capstan (not shown) of a cassette player. In operation, the capstan of the cassette player directly drives the roller 404 which in turn drives the roller 402. The capstan is maintained in abutment with the roller 404 by means of a fixed retaining wheel 406, the latter also preventing the pressure roller (shown in broken line at 408) of the cassette player coming into direct contact with the capstan and ensuring that the pressure roler 408 acts only on the roller 402. The recording tape (referenced 410) is driven between the pressure roller 408 and the roller 402. The rollers 402 and 404 can be spring biased into their rest positions to ensure good contact with one another and with the capstan.

FIG. 15 illustrates a ninth embodiment of a tape cassette according to the present invention which is generally similar to the arrangement shown in FIG. 14, similar parts therefore being accorded the same reference numerals but with 500 added. In the embodiment of FIG. 15, however, the two rollers 502 and 504 are mounted for sliding movement at an angle to one another. The roller 504 is driven by the capstan (referenced 512) of the cassette player and has a reduced diameter portion with which the roller 502 is engaged. As in the previous embodiment, the recording tape 510 passes between the roller 502 and the pressure roller 508 of the cassette player. A retaining spring (not shown) is provided to maintain the rollers 502 and 504 in contact.

A tenth embodiment of a tape cassette according to the present invention is shown in FIG. 16, in which two mutually engaged idler rollers 520 and 522 are mounted on a triangular plate 524 which is pivotable about an axis 526. In use, the pressure roller (shown in broken line at 528) of a cassette player pinches the tape against the roller 522, drive being transmitted from the capstan (not shown) of the cassette player to the roller 522 by way of the roller 520. The rollers 520 and 522 are shown in their rest position in the absence of the capstan: when the capstan is present, it pivots the roller 520 about the pivot axis 526 and thereby moves the roller 522 into contact with the pressure roller 528.

FIG. 17 shows an eleventh embodiment of the tape cassette according to the present invention, in which a drive system for the recording tape comprises a gear wheel 530 having a reduced diameter central portion (not shown) with which a sleeve 532 is engaged. In use, the capstan of a cassette player is received within the sleeve 532 and drives the gear wheel 530, the latter in turn driving the sleeve 532. The tape is pinched between the sleeve 532 and the pressure roller (shown in broken line at 534) of the cassette player. A retaining wheel 536 assists in maintaining the sleeve 532 in position and a retaining arm 538 prevents the roller 534 from coming into contact with the gear wheel 530, or forcing the sleeve 532 into contact with the capstan.

In each of the embodiments of FIGS. 14 to 17, the tape is transported at a slower speed than in a conventional cassette. If desired, the hub drive to the tape spool can be replaced by a slipping clutch rim drive, as in the embodiments of FIGS. 2 to 8. If, however, such a rim drive is not provided, it is possible to modify a conventional tape cassette into any one of the forms shown in FIGS. 14 to 17 merely by cutting away a portion of cassette which contains the hole through which the capstan enters and by replacing the cut-away portion with a preassembled unit containing the tape drive system.

FIGS. 18 to 20 show a twelfth embodiment of a tape cassette according to the present invention in which the tape transport speed is less than that for a standard cassette. The recording tape (referenced 540) is pinched in use between the pressure roller 542 of a cassette player and a sleeve 544 in which the capstan 546 of the cassette player is received, the sleeve 544 being mounted resiliently within the cassette by a spring 548. The sleeve 544 has two reduced diameter portions 550 adjacent its ends, and the spring 548 has two loops 552 which are spaced apart axially of the sleeve 544 and which rotatably receive the portions 550 respectively. The axial gap between the loops 552 provides sufficient clearance for the recording tape 540 and the pressure roller 542 to engage a central portion 554 of the sleeve. Preferably, the sleeve is constructed from a tubular nylon spigot 556 to the external surface of which a rubber ring 558 is adhered, the rubber ring forming the central portion 554 of the sleeve. The sleeve is shown in detail in FIG. 20.

FIG. 21 illustrates a drive slip arrangement for a tape spool which can be applied to any of the embodiments described above. The tape spool (referenced 560) is driven on its rim by a driver 562 which may be a slipping clutch drive. Two retaining rollers 564, one of which normally contacts the spool rim, are provided together with a pivot roller 566 which also normally contacts the spool rim. The spool is driven in an anticlockwise direction, and increase of the tension in the recording tape (not shown) beyond a certain level causes the spool to ride up on the pivot roller 566 and clear the driver 562. With the spool drive thus removed, the tension in the tape drops and the spool returns to its initial position in which it once again contacts the driver 562. A spring biased roller 568 in abutment with the spool rim prevents the spool from being displaced by too great an extent.

Finally, it will be appreciated that the tape speed past a tape head may be at any desired value depending primarily on the dimensions of the rollers in the tape drive system.